DE3022162C2 - Equipment on industrial robots to limit the swivel range of arm parts - Google Patents

Description

- that in the discharge line of the swivel drive ίο

of the respective arm part (5, 6) a throttle device with two rotatable relative to one another,

a closing element (16) or one of these parts permissible pivoting range of arm parts connected to the (6) is arranged and so designed. Features of the preamble of claim 1.
det is that the closing member (16) develop the opening. It is well known that hydraulic pivoting drives (14) when the arm part (5) approaches the one be for industrial robots with larger designs or very different end positions of its permissible high torques. These are desirable, on the one hand, since the swiveling range (19) increasingly allows the construction of an extremely efficient system remaining to close the minimum cross-section with short work cycles. On the other hand, it is dimensioned in such a way that in the area (20), however, increased precautions must only be taken within the permissible swivel range (19) that incorrect movements of the arms in swiveling the arm part in crawl gear and the objects handled by them are possible is; 25 prohibited areas with security prevented

- that the end positions of the permissible swivel are.

rich (19) of the arm part (5, 6) have activatable industrial robots of known design for

Limit switches are assigned, which are fixed to a limit stop preventing such erroneous movements

gen monitoring control connected end stops, which are often designed as stop buffers

are, 30 are (example: KUKA company print

- and that the end position monitoring control SK 37-015-32). End stops of this type can be at least partially arranged for when a limit switch responds so that they can, for. B. the Dreden arm part by blocking an industrial robot arm around the vertical Zennes swivel drive and with manual tral axis only in a desired, limited Beler actuation of a reset button (T \, T ₂ ) allow a 35 rich, with which the adjustment of the Robot to reset movement of the arm part in crawl gear a given application is facilitated. The hydraulic swivel control controls the torques up to the permissible swivel range (19). drives (e.g. 20,000 Nm and more) are, however, in one

such a solution very heavy attacks and corresponding

2. Safety device according to claim 1, 40 related fasteners required. Also can characterized in that the end positions monitor the abrupt stop of the pivoting movement at these control when responding to an arm strike to damage the industrial robot Partly assigned limit switch the rotary drive itself and on the objects handled by it be all arm parts (5, 6) of the industrial robot. It is true that both linear work- (1) blocked. 45 tendency hydraulic cylinders (DE-OS 21 52 641) as well

3. Safety device according to claim 1 and 2, with hydraulic rotary drives (DE-OS 20 54 575), characterized in that by the manual loading progressively damping hydraulic end stops actuation of the reset button (Tt, T ₂ ) only knows where a on one of the two moving swivel drive of the closing element located outside the permissible part when approaching the swivel area (19) located arm part (5, 6), 50 end position the cross-section in the discharge line of the hydraulic and only for the return swivel direction, lifting hydraulic drive increasingly closed and thus bar. the movement smoothly, i.e. with a given

4. Safety device according to claim 2, there- delay characteristic, automatically to a standstill, characterized in that the blocking brings all. By installing such progressively attenuating swivel drives, the hydraulic stops in the swivel drives of the arm parts of industrial robots outside the permissible swivel range (19) can, however, use the reset button to prevent the arm parts (5, 6) from occurring, especially in industrial robots. (Tu T ₂ ) back problems in the permissible swivel range cannot be solved sufficiently.

has been controlled. The movements of industrial robots are in

5. Safety device according to one of the claims 60 generally automatically according to a predetermined program 1 to 5, characterized in that it is controlled as a border gram, the program in particular pushing a button for each arm part (5, 6) during the shutdown the swivel drive controls movements of the activated limit switch (A) at the position of the arm part within the permissible swivel end points of the prescribed work swivel range (19). These working pivoting movements, and one each when the right or left b5 is exceeded, should of course all lie within the maximum pivoting range of each arm part that is relevant to the end position of the permissible pivoting range (19). Crosstalk end position limit switch (R, L) have exceeded this permissible swivel range and that the end position monitoring systems are therefore either due to a programming error or

3 4

on a faulty working of the program-controlled can. However, this is only one avenge

old facilities. If such a case occurs, responsive safety equipment can be used in the event of malfunctions.

an end stop, if necessary hydraulically limited, rather about the operational shutdown of the

Although the arm part in question forcibly prematurely wave in certain positions, and it will not

stop, d. H. in the execution of the faulty, over 5 a permissible swivel range of the WeUe limited, many

Swiveling beyond the permissible range, the shaft runs before its speed reaches the

prevent failure. But this is the cause of the faulty creep speed has been slowed down, in the whole

stick swivel command not eliminated.

The invention is illustrated using one of the figures

the same case may occur again and the anio illustrated embodiment is explained in more detail,

strike repeatedly have to come into action, which is the processing of the signals or signaling devices in

on the one hand, a faulty program sequence of the Ro a block diagram is shown.

boters and, on the other hand, a constant source of danger A b b. 1 shows an industrial robot schsmatically

means also is after running on a sol-linked swivel joints.

chen, if necessary hydraulically damped end positions 15 A b b. 2 shows a rotary leadthrough in section

stop the restart or retraction of the ring channel assigned to the sequence.

The arm part of the industrial robot concerned is not shown in Fig. 3 shows a section corresponding to that in

without any problems and often with an additional input A b b. 2 specified cutting line.

endangerment of the objects lying in the work area Fig. 4 shows one of the Fig. 3 corresponding

and the like possible. 20 Section with the locking member in engagement.

The invention is based on the object of providing a simple Fig. 5 shows a block diagram for processing

Before, cheap and space-saving safety device that is created in the course of end position monitoring

of the type mentioned to create, on the one hand, the movement signals and manual resetting,

of the arm parts over their permissible swivel range An industrial robot 1 has several axes 2, 3

also automatically, reliably and gently prevents 25 and 4 with associated, not shown

and thereby damage to the industrial robotic swivel motors. The hydraulic supply of the

the endangerment of objects swivel motors takes place via hydraulic rotary

and people in its vicinity and avoiding cues, which has the advantage that to the

on the other hand, if such an incident occurs, arm parts 5 or 6 between axes 2 and 3 or 3 respectively

ensures that the further operation or the reinstallation 30 and 4 fixed pipelines can be laid. One

driving the industrial robot safely, namely rotary feedthrough 7 is in A b b. 2 excerpts

only by means of a separate one that takes into account the posed and has a first part 8 of cylindrical

Routine permitting the cause of the error is possible. Cross-section which in a corresponding hole The inventive solution to this problem is performed in a second part 9. Part 9 includes Claim 1 stated. Advantageous further embodiment 3s axial distance two seals 10 and 11 arranged

Services are the subject of the subclaims. net, between which a ring channel 12 is located in

The invention is thus based on the principle in which an opening 13 opens within the part 9 approach of the respective arm part to the limit of its permissible swivel range the movement by means of hy- opposite, which leads to a longitudinal bore 15 in part 8 hydraulic damping does not completely stop, but 40 propagates. In the ring channel 12 there is a only to throttle to crawl and then within locking member 16, which with the help of a clamping screw the crawler zone, the limit switch-controlled end 17 can be attached even if the locking member 16 the If the gene monitoring control is effective, the opening 14 is fully covered, a broom with 18 remains. This significantly improves safety, as the minimum flow cross-section is drawn. The allowed yes, not only the movement of the arm part 45 swivel area in question is denoted by 19. Inside the with simply stopped, but its swivel drive and 20 designated area, the locking member 16 is fully in the if necessary, all rotary drives of the Indu intervention.

strieroboters are blocked. The industrial robot For an explanation of the function, A b b. 3 and

cannot simply be assumed by further control commands or 4, whereby it is assumed that the not

by reversing the hydraulic loading again 50 shown in more detail, starting from the in

be set in motion, but this is the separate A b b. 3 drawn central position will be actuated and the

Derte actuation of a reset button required, which ring channel 12 the flow of the pressure medium according to the

usually will not happen without first serving the way TT . According to the movements of the

The cause of the malfunction got to the bottom of the swivel motor, a relative movement between

be. The return in the permissible pivoting 55 see the parts 8 and 9 take place, that is, that

rich in takes place in the creeping striker, the opening 14 is approached without any-

gang, which means that this often particularly thing to take effect for the time being. Finally begins

The risk associated with the problematic process is largely the closing of the opening 14

is reduced. the flow cross-section in one of the shape of the

It is true that DE-OS 19 22 644 describes a device 60, opening 14 and the shape of the closing member 16 reduced to stop a shaft in a predetermined angle-dependent manner, is known to build up in the shutdown, in which the shaft by means of a hydraulic rin continuously increasing counter pressure, and the lisch-controlled friction clutch up to the creep speed of the swivel motor is steadily slowed down and only after reaching the ger. It is only at the discretion of the designer how Creep speed of a fixing 65 blocking the shaft will be small, the minimum flow cross-section 18 device is engaged, whereby a hydrostat is possible. In any case, the aim is to achieve the swiveling, also the further rotation of the shaft in the creep speed motor until a creep speed is reached verbis to engage the fixing device, because at such a low speed the

Risk of destruction or damage already high is reduced and with the help of other measures such. B. an emergency stop circuit can be effected. Such Measure can e.g. B. caused by approaching limit switches. The function of such a 5 gen end position monitoring is from A b b. 5 can be seen.

For the axis 2 shown as an example, there is ongoing monitoring of compliance with the permitted swivel range 19 z. B. by a not shown, connected to the swivel drive cam, which holds a limit switch (A), also not shown, activated in (and only in) the permitted swivel range 19, in connection with one each - not shown

- Limit switch on the left (L) and on the right (R) limitation of the permitted swivel range IS. As soon as the limit switch (A) registers that the permitted swivel range 19 has been left, the EMERGENCY STOP device is activated for the entire industrial robot, either (for end position L) via the limit switch (L) with a memory function, or (in the case of end position R) via the limit switch (R) with memory function, or, if the relevant limit switch (L) or (R) fails, via a logic unit which, when the 3 conditions are simultaneously present

- Part-turn actuator outside the permitted range

- End position L not registered

- End position R not registered

30th

also activates EMERGENCY STOP. In the latter case, there is a fault caused by the normal reset routine cannot be eliminated and soIL

The EMERGENCY STOP control of the industrial robot blocks all axes in both the L direction of rotation and the R direction of rotation and the industrial robot comes to a standstill.

A reset from the end position is only effected by manual actuation of the reset button TX or T2 opposite the respective Endlager.2uflaufbewegung in the direction of rotation, whereby at the same time

- Regardless of the hydraulic device according to the invention - in terms of control on crawler gear is switched. As soon as the logical linkage conditions

- end position L (or R)

- Reset command

- Creeper

- Direction of rotation R (or L)

are present at the same time, according to the invention, the actuation of the swivel drive 2 for the return movement in creep speed in the direction of rotation R (or L) with simultaneous release of the blocking of the direction of rotation R (or L) only for this axis.

The reset movement reactivates the limit switch (A) and deactivates the limit switch L (or R) when the permitted swivel range is reached again, whereby the control of the EMERGENCY STOP device is canceled and the industrial robot is again with all axes and for all directions of rotation Axis is functional.

For this purpose 4 sheets of drawings

Claims (1)

1 2 tion both from the range limit switch (A) In combination claims: combination with one of the end position limit switches (R, L) and from the range limit switch (A) alone. 1. The safety device on industrial robots can be determined Limitation of the permissible swivel range of 5 6. Safety device according to one of the claims arm parts, by means of associated hydraulic marriage 1 to 5, characterized in that the Part-turn actuators can be swiveled, the closing element (16) being adjustable and identified by means of a clamp, screw (17) can be fastened